Issue 120825 - Curve bitmap conversion problem
Summary: Curve bitmap conversion problem
Alias: None
Product: Draw
Classification: Application
Component: formatting (show other issues)
Version: 3.4.1
Hardware: PC Windows XP
: P3 Major (vote)
Target Milestone: ---
Assignee: AOO issues mailing list
QA Contact:
Depends on:
Reported: 2012-09-05 21:41 UTC by Lance Gropper
Modified: 2012-09-05 22:35 UTC (History)
1 user (show)

See Also:
Issue Type: DEFECT
Latest Confirmation in: ---
Developer Difficulty: ---

Demonstration of problem. (9.22 KB, application/
2012-09-05 21:41 UTC, Lance Gropper
no flags Details

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Description Lance Gropper 2012-09-05 21:41:53 UTC
Created attachment 79303 [details]
Demonstration of problem.

When a curve is converted to a bitmap, the resulting bitmap is larger than the curve by 10%, and includes empty space on two sides.

The attached file shows the problem step-by-step. The goal was to create 1/4th of a circle which would have been 2" in diameter, with the thickness of the line being 0.2". The grid was set to 0.05" and set to snap. Antialiasing is off. Going from left to right in the image:

Step 1: a line was drawn at a 45 degree angle, such that horizontally and vertically, the square the line occupied was 0.9"x0.9" This was done because once the line thickness was changed, from a previous bug I reported, you have to compensate for the line thickness.

Step 2: The thickness of the line was changed to 0.2"

Step 3: The line was converted to a curve, and the "handle" for the lower point were moved so that it was 0.45" vertically, directly above the lower point, and the handle for the upper point was moved so that it was 0.45" horizontally directly to the left of the upper point.

Step 4: The curve had to be adjusted, because the result at that point didn't fit in a 1"x1" box - it was too small, so the lower left point was moved down and to the left by 0.1" and the whole curve was moved. Once repositioned, the handles for the points were adjusted to 0.5" each.

At this point, we have what we want visually - it is a curve which is 0.9"x0.9" with a 0.2" thickness, so it occupies a square which is exactly 1"x1".

Step 5: It was converted to a bitmap, using Modify -> Convert to Bitmap. You have to click on the bitmap to see the problem, but the bitmap is now 1.1"x1.1" with 0.1" of white space on the right and on the bottom.

What it looks like it might be doing is trying to extrapolate what the edges of the curve would look like, and is adding extra space for the extrapolation.
Comment 1 Regina Henschel 2012-09-05 21:56:17 UTC
This problem is already tracked in your issue 120707.

*** This issue has been marked as a duplicate of issue 120707 ***
Comment 2 Lance Gropper 2012-09-05 22:01:13 UTC
Not a duplicate - because the same person reported two different bugs means they are duplicates? Please re-read and look at the example.
Comment 3 Lance Gropper 2012-09-05 22:01:48 UTC
This bug is being reported with the work-around for the previous one reported...
Comment 4 Regina Henschel 2012-09-05 22:26:11 UTC
You had two problems
(1) When converting to bitmaps, thick lines generate additional space ==> bug 120707
(2) convert to bitmap adds 1 pixel ==> bug 120744

And Armin, our expert for graphic, has already looked at both. Be assured, your reports are heard.

If I have overseen something essential, please explain it.
Comment 5 Lance Gropper 2012-09-05 22:35:23 UTC
The first problem turned out to be with Anti-aliasing and due to the thickness of the curves. That completely explains the problem. Armin determined the previous problem was not a bug and closed it, and I agree with his decision. This second problem isn't with anti-aliasing or curve thickness, and I don't see anything which could explain it (it's almost as if having the endpoints set to none is the same as having them set to rounded). Collectively, I'm trying to find a way to do this as it's holding up software development that I need the graphics for. So while this problem may not come up for everyone and may not be a blocker, to me, it is pretty critical. I found another work-around, but it apparently only works on curves, and has another bug associated with it (rotating cropped bitmaps only rotates the cropping - it doesn't rotate the bitmap). Wait a minute - that might be a work-around. Create these shapes, convert them to bitmaps, let the problems occur, then crop the problems out. I'll give that a try. So for example, in the sample drawing I sent, I could crop off the excess 0.1" on the right and bottom, and it should be perfect, unless of course, the file export puts it back in or something...